The server encountered an internal error and was unable to complete your request

Nextcloud version: ? Perhaps 16?
Operating system and version Ubuntu 16.04.6 (no gui, I believe it is Ubuntu Server).
This is the official NC VM by Daniel Hannson
Apache version: (2.4.18)
PHP version: ?

The issue you are facing:
My NC server has been working flawlessly for a while now. However recently (a week or so ago) I noticed my cell phone’s NC app was notifying me of some errors with syncing. I tried to log in to my server via a web browser and recieved the following message…

“Internal Server Error
The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.”

I have rebooted both the NC VM and the host computer and still am seeing the same error message. I cannot log in to my NC server via a web browser - can’t even load the login page.

If you’d like to know more information, please let me know which commands I should I type in the NC VM and I’ll paste it in this topic.

Is this the first time you’ve seen this error? (Y/N): Yes

Steps to replicate it:

  1. Attempt to log in to web my NC server browser

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

How do I find my path-to-nextcloud and my config.php file?

The output of your Apache/nginx/system log in /var/log/____:

I found my /var/log/apache2 directory and have several files there. Which do I open and how?